Agricultural tractor guide



Dec. 2 1926. 1,611,540

' R. D. MCALLISTER AGRICULTURAL TRACTOR GUIDE Filed UGC. 24. 1925 2Sheets-Shee 2 31a/vanto@ Ahi?. MCA zuster my M Patented Dec. 21, 1926.

UNITED STATES RALPH D. McALLISTER, F SALISBURY, MARYLAND, ASSIGNOR VTOEDWARD E. TULL,

OF PRINCESS .ANNEy MARYLAND. I A

AGRICULTURAL TRACTOR GUIDE.

n Application filed December 24, 1925.

The invention relates to automatic steering means for tractors employedin connection with agricultural machinery, whereby a plow, or otherimplement, after being properly started will continue to operate withoutbeing manned and, in the event' of the implement getting off its course,it will automatically stop by the grounding, or otherwise interruptionof the controlling circuit of the tractor.

rlhe invention provides a steering guide mechanism which may be readilyapplied to any type of tractor, and which is controlled by the furrowformed by the shovel of the implement hitched to the tractor to bepropelled thereby, the guide mechanism cmbodyimg` a pilot wheel to runin the furrow and yieldably held therein both by a vertical and a.lateral pressure.

While the drawings illustrate a preferred embodiment of the invention,it` is to be understood that in adapting the means to meet specificneeds and requirements the design may be varied, and such other changesin the minor details of construction may resorted to within the Scope ofthe invention, as claimed, without departing from the spirit thereof.

For a full understanding of the invention and the merits thereof,reference is to be had to thefollowing description and the drawingshereto attached, in which,-

Figure 1 is a top plan view of a conventional type of tractor andagricultural implement hitched thereto, provided with an automaticguiding mechanism embodying the invention,

Figure 2 is an enlarged sectional view about on the line 2 2 of Figure1, looking` in the direction of the arrows, the tubular member of thedownwardly exerting pressure means being in section, v

Figure 3 is a vertical sectional view on the Yline .3*3 of Figure 2looking in the direction of the arrows, and

Figure 4 is a fragmentary sectional view on the line 4 4 of Figure l,showing the parts on a larger scale.

Correspondingand like parts are referred to in the following descriptionand designated in the several views of the drawings by like referencecharacters.

The numeral 1 designates a tractor which may be of any make and isillustrated to demonstrate the application of the inven- Serial No.77,561.

cultural implement which is hitched to the.

tractor to be drawn over the field thereby. The implement 2 is providedwith a furrow forming shovel 3, which may be of any design or type. Thetractor is provided with steering wheels 4 and 4a which are connected inany usual or preferred way, so as to be operated by the usual hand wheel5 when it is required to steer the tractor by hand. The numeral Gdesignates a conductor whichV leads from the magneto 7, or other sourceof current supply for the ignition system of the tractor power unit. Theconductor l is electrically connected with a fixed contact 8 mountedupon ythe, frame of the tractor and electrically insulated therefrom. 'Amovable contact 9 is connected with the steering mechanism and, asshown, is attached to the steering arm 10 upon the furl row side of thetractor, so that in the event ofthe pilot wheel of the guiding mechanismleaving the furrow, the magneto will be grounded, or the supply ofcurrent to the ignition system will be interrupted, thereby causing thetractor to stop and preventing it from running wild.

The guiding mechanism comprises a frame which is connected to thetractor to have a limited vertical and lateral movement and this frameis narrow and elongated and comprises an outer member 11, an innermember 12 and a front cross bar 14. The rear end of the outer member 11is connected to the outer end of the spindle 13 at the furrow side ofthe tractor. The rearportion of the inner member 12 is offset laterallyand formed with a slot 12a' to receive a bolt or like fastening 14 whichis mounted in the front axle 15 of the tractor wherebyprovision is hadfor a limited pivotal movement of the guiding frame which isy essentialto the proper operation ofthe mechanism as a whole. The outer or forwardend of the guiding frame has a limited vertical movement and is suppliedwith a fork 16 in which is mounted a pilot wheel 17 which is adapted to.run in the guiding furrow 18. A contractile spring 19 is attached at oneend to the forward portion of the guiding frame and its opposite end isconnected tothe tractor and. as shown, a bracket 20 projects forwardlyfrom the landside of the tractor and receives a screw 21 to which theinner4 end of the spring 19 is attached. A hand (iii nut 22 is mountedupon thens'crew 21 and cooperates wit-h the bracket 2O to properlytension the spring, whereby the front 'en'd ot the guidingr Vtraine is"Iiorinally drawn in wardly to keep the pilot wheel 17 in contact withthe landside of the furrow 18.

A, yieldable connection is interposed between the outer, or forward, endOt the guiding traine and the ltractor and exerts a downward pressure tohold the pilot wheel 17 within theufu'ri'ow 18. "his yieldableconnection eniprises sections '23 and Q4 `disposed to have, a telescopicconnection Aand ,an interposed helic'alspriiig -25 which is housedVwithin the ytubular section 2li and confined betweenth'e rear endsot'the telescopinfoT sections. The tubular section 24 is connected to thetrent portion of tie tractor-,1in a 'manner to admit 'of the forwardendet the Section'liaiiiiifjiv 4a liinite'd Vertical and lateral playcontorni to corresponding "movenients of the 'front end of the guiding`traine. The loiilewtorward lend ot the 'section 23 is loos'elf.7clainpedto the front cross bar 11i otwtlie guiding' traine, as indicatedat 27. In the practical operation or" the invention, the plow 2, orother agriculturaliinplement tobe drawn 'overtheiielch is hitched in anydeterminate way, to the tractor 1 and the latter is'iequipped at itsfront end lwith the vaultoin'atic Asteering` nieans. lt is essentialVthat'a tui-row he provided about Athe tield'to be plowed, or otlferwiseprepared, 'and this initial furrow :may be prepared in 'any preferredway, either by'ine'ansot an ordinaryv plow, or by the usfe ot thetractor which is operated 'an attendant ,the end portion ot thisinitial, or'circunis, ibiiifh3 vfurrow teriuii'uiting troni thebegiiinii'ig'ot the furrow, a distance eorrespondingl with the spa-'1edesired between the fu'ri'oiifsfth'e end portion ot such initial furrowbeinf'r extended a 'short Vdistai'ice parallel with b'eginni'i v ot theinitial furrow and spaced therefrom the req'iiir'ed distance,atterwhich, the inechanisin is adjutcd s'o that the 'pilot wheel 17 'andthe wheels ot' :the tract'oraiid i'nipleii'ient 2, o'i the t'ui'r'owside, enter the! initialportion ot the prepared tu i'iow. Theni'echanisin l'ieinn thus adjusted, the vinot'or ot v'thetractoruisstaited and tire operation be'coines autmiiati'csince thetractor isfsteered by the pilot wl'ieel 17 i.iuufiniiii in furrow 18.The landside 'ot the yfurrow 18 is steep, as showh nio'st clearly inFigure 3, 'and the 'spring 19 operates to Vlulvdfthe pilot wheeli'vagalinst't-he vland"side oi the furrow and should the pilotlwheeltronran7 cause, l'eaife the furrow which must by way Vot the outersidepoltin jot the fheld, the iront end ot'the steering' traine willni'ove outii'ardlw', thereby bringing the contact 9 in engagement withthe contact 8, thereby grotinding` the magneto, or otherwiseinterrupting t-he circuit upon which the motor ot the tractor 'dependsfor its operation 'and in c'ons'e'f'p'ience, the tractor is brought to astandstill. lWhen the mechanism is t'unctionin'g properlyv it circlesthe iield and works troni the outer margin thereof towards the center ina continuous spiral path, aswill be readily appreciated.

Having thus described the inifention, I claim:

1. Ain automatic. steering;- inechanisni for a Itraf-tor, the saineconsistingl ot an 'elon- Igated guiding; tranie 'connected to tlieente;I end ot' the spindle on the furrow side ot thetractor and haring aloose vconnection with the `traine ot tl'ietractor, a pilot wheel 'atIthe outer, 'or forward, end o1" the guiding` traine, yieldable meansbetween ,the guiding fra'n'ie 'and the tractor, tending toninove theforward end ot the guiding trarne landwai'd and a yieldable connectionbetween the tractor and lthe 'forward end ot said guiding tr nie ton'ornially exert a downward pressure thereonto hold the pilot wheelwithin the guiding turiOW. Y

guiding device tor autoinaticall)v steeringq a Ytractor the sainecouiprising` a sulzfstantiallj,Y U-shai'ied traine, having;` its 'outerineniber conn'eetcd to the outer cud ot the 'tractor` spindle, upon thefurrow side `and haring; its inner n'ienll'ier loosely1 cou-'iiezt'edfwi'tli the tractoi-a pilot wheel at the outer or i'oi'waid endot thc guiding traine, Aa yieldalile rounection between the guiding:traine and tractor norn'ial'ly tending` to more the t'ront und ot the"guidingl traine land- "ward and a vieldal'ile connection between theguiding traine and tractor normallyy 'cx- Vertingl alowuward `pressureupon the iront end ot the {guidii'ig vtraine to hold vthe pilot wheel'in a guiding; furrow.

3. The combination witlra tractor, 'olf a lguiding traine otsubstantially Urlorin haring its outer nieinbei connected to the outerend ot' the spindle on the Yfurrow side ot the tractor, and havingytherear portion ot the inner nienlber laterally ol'i'set and long i dinallyslotted, ,fastening means connecting the slotted nienbcr to the tractor,a pilot wheel at the L ont end Aotthe guiding` iframe. 4a spring betweenthe tractor and guiding raine tending to nieve the latta' inwardlj,Y atits 'toi-'ward end and a yieldable telescopic co'inection between the'guiding traine and traetor norinall;7 tending to press thc iront end ofthe guiding' traine downwardl)Y and hold the pilot wheel in the guidingfurrow. Y

l n testini'omv wher-noti afrit; inv signature.

niinrn n, timinnis'rnn.

